使用网页制作一个MQTT客户端


<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>MQTT Light Control</title>
    <link rel="stylesheet" href="styles.css">
</head>
<body>
    <div class="switch-container">
        <label class="switch">
            <input type="checkbox" id="lightSwitch">
            <span class="slider round"></span>
        </label>
    </div>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/paho-mqtt/1.0.2/mqttws31.min.js"></script>
    <script src="script.js"></script>
</body>
</html>

styles.css 文件

这个文件主要定义了界面元素的风格。

body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #f4f4f4;
    margin: 0;
    font-family: Arial, sans-serif;
}

.switch-container {
    text-align: center;
}

/* The switch - the box around the slider */
.switch {
    position: relative;
    display: inline-block;
    width: 60px;
    height: 34px;
}

/* Hide default HTML checkbox */
.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

/* The slider */
.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    -webkit-transition: .4s;
    transition: .4s;
}

.slider:before {
    position: absolute;
    content: "";
    height: 26px;
    width: 26px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    -webkit-transition: .4s;
    transition: .4s;
}

input:checked + .slider {
    background-color: #2196F3;
}

input:focus + .slider {
    box-shadow: 0 0 1px #2196F3;
}

input:checked + .slider:before {
    -webkit-transform: translateX(26px);
    -ms-transform: translateX(26px);
    transform: translateX(26px);
}

/* Rounded sliders */
.slider.round {
    border-radius: 34px;
}

.slider.round:before {
    border-radius: 50%;
}

script.js文件

这个文件是核心逻辑，代码如下：

const clientId = "1fc9600";
const client = new Paho.MQTT.Client('localhost', 8083, clientId);
const lightTopic = 'light002';


let connected = false;

// called when the client connects
client.onConnectionLost = function (responseObject) {
    console.log("Connection lost: " + responseObject.errorMessage);
    connected = false;
};

// called when the client loses its connection
client.onConnect = function (responseObject) {
    if (responseObject.errorCode === 0) {
        console.log("Connected to MQTT broker!");
        connected = true;
    } else {
        console.log("Failed to connect, return code: " + responseObject.errorCode + ", error message: " + responseObject.errorMessage);
    }
};

// called when a message arrives
client.onMessageArrived = function (message) {
    console.log("Message arrived: " + message.payloadString);
    if(message.payloadString === 'ON') {
        document.getElementById('lightSwitch').checked = true;
    } else {
        document.getElementById('lightSwitch').checked = false;
    }            
};


// connect to the MQTT server
client.connect({onSuccess: onConnect,  useSSL: false});

// subscribe to the topic
function onConnect() {
    console.log("Connected to MQTT broker!");
    connected = true;
    console.log("Subscribing to topic: " + lightTopic);
    client.subscribe(lightTopic, {qos: 0});
}

document.getElementById('lightSwitch').addEventListener('change', function (e) {
    if (connected) {
        const message = e.target.checked ? 'ON' : 'OFF';
        client.send(lightTopic, message, 0, true);
    }
});